Could also be the tomato hornworm. Google it for the images so you can see what they look like, creepy. I had one that ate the entire tops off my tomato plants before I found it. They are difficult to spot because they blend right in with the foliage.

This is probably the tomato hornworm doing this damage. They blend in nicely with the leaves and can ravage a healthy plant in a few days. Look for pellet like droppings on the leaves and on the ground. They are gross! Good luck with the garden.